Ferrite Elements for Hybrid Microwave Integrated Systems

Complete realization of the potentialities of hybrid microwave integrated circuits will require both semiconductor and ferrite elements. This paper presents performance data for several microstrip ferrite devices that can play an important role in the exploitation of microwave integrated circuits. Data on both fixed-field and latched microstrip junction circulators are given including a fixed-field circulator with less than 0.4-dB loss and greater than 20-dB isolation over the 6.5- to 9.3-GHz band. The characteristics of microstrip meander-line phasers are discussed, and a simple, rugged technique for fabricating single-crystal YIG devices by embedding the YIG element in the substrate is presented.     

Ferrite elements for hybrid microwave integrated systems

Complete realization of the potentialities of hybrid microwave integrated circuits will require both semiconductor and ferrite elements. This paper presents performance data for several microstrip ferrite devices that can play an important role in the exploitation of microwave integrated circuits. Data on both fixed-field and latched microstrip junction circulators are given including a fixed-field circulator with less than 0.4- dB loss and greater than 20-dB isolation over the 6.5- to 9.3-GHz band. The characteristics of microstrip meander-line phasers are discussed, and a simple, rugged technique for fabricating single-crystal YIG devices by embedding the YIG element in the substrate is presented.     

New multilayer planar transmission lines for microwave andmillimeter-wave integrated circuits

New types of planar transmission lines employing multilayer structures are proposed for possible applications in microwave and millimeter-wave integrated circuits. Detailed investigations are presented through numerical results calculated using the spectral domain technique. The newly proposed transmission lines have many attractive features such as a large impedance range, flexibility and ability to realize complicated, densely packed integrated circuits, as well as miniaturization through the use of thin dielectric layers. Additionally, they possess all of the inherent advantages of the CPW and microstrip line. Their use in microwave circuits is exemplified through a low-pass filter realized using the new slot-coplanar lines with less than 0.5-dB insertion loss and better than 20-dB return loss. The filter's measured and calculated performances also agree well     

Status of Lumped Elements in Microwave Integrated Circuits---Present and Future

The use of lumped elements in microwave integrated circuits (MICS) is discussed. The design, fabrication, and performance of networks used in both active and passive circuits are described. Studies on amplifier impedance matching and transforming networks have resulted in the achievement of a 35-dB-gain 6-W-CW 26-percent-efficient amplifier at 2.25 GHz using only lumped elements. Construction of lumped-element low-pass filters and 3-dB quadrature hybrids at S band have produced circuits much smaller than, but with performance comparable to, microstrip distributed circuits. At C band a large-impedance transformer operating as a filter had less than 0.4-dB loss for an impedance transformation close to 20:1. The performance of lumped-element circuits through X band is compared with that of distributed circuits from the standpoint of size, economy, and technological applications. Lumped-element circuits are competitive with distributed circuits through 6 GHz and are practical through 12 GHz.     

Single feed proximity coupled circularly polarized microstripmonofilar Archimedean spiral antenna array

The analysis is presented for a microstrip feed proximity coupled monofilar Archimedean spiral four-element antenna array. Interactions between the microstrip corporate feed and the radiating elements are rigorously included. Results demonstrate that circular polarization can be achieved with proper spiral arm length. Polarization of either sense is controlled by the location of the feedline. The 3-dB axial ratio (AR) and voltage standing wave ratio (VSWR) bandwidths are 9%. The antenna is small (2R/λ₀=0.33) and the interelement spacing is 0.51λ₀. The microstrip feed produces a completely planar antenna system, which is compatible with microwave integrated circuits (MIC) and monolithic microwave integrated circuits (MMIC)     

Embedded microstrip interconnection lines for gigahertz digitalcircuits

Transmission line structures are needed for the high-performance interconnection lines of GHz integrated circuits (ICs) and multichip modules (MCMs), to minimize undesired electromagnetic wave phenomena and, therefore, to maximize the transmission bandwidth of the interconnection lines. In addition, correct and simple models of the interconnection lines are required for the efficient design and analysis of the circuits containing the interconnection lines. In this paper, we present electrical comparisons of three transmission line structures: conventional metal-insulator-semiconductor (MIS) and the embedded microstrip structures-embedded microstrip (EM) and inverted embedded microstrip (IEM). In addition, we propose closed-form expressions for the embedded microstrip structures EM and IEM and validate the expressions by comparing with empirical results based on S-parameter measurements and subsequent microwave network analysis. Test devices were fabricated using a 1-poly and 3-metal 0.6 μm Si process. The test devices contained the conventional MIS and the two embedded microstrip structures of different sizes. The embedded microstrip structures were shown to carry GHz digital signals with less loss and less dispersion than the conventional MIS line structures. S-parameter measurements of the test devices showed that the embedded microstrip structures could support the quasi-TEM mode propagation at frequencies above 2 GHz. On the other hand, the conventional MIS structure showed slow-wave mode propagation up to 20 GHz. More than 3-dB/mm difference of signal attenuation was observed between the embedded microstrip structures and the conventional MIS structure at 20 GHz. Finally, analytical RLCG transmission line models were developed and shown to agree well with the empirical models deduced from S-parameter measurements     

Single-feed circularly polarized microstrip ring antenna and arrays

An analysis is presented for a microstrip-feed proximity-coupled ring antenna and a four-element array. Interactions between the embedded microstrip feed and the radiating element(s) are rigorously included. Results demonstrate that circular polarization of both senses can be achieved with a ring antenna with proper design of two inner stubs located at angles of ±45° with respect to the feedline. Theory and experiment demonstrate an axial ratio 3-dB bandwidth of 1% and the voltage standing wave ratio (VSWR) <2 bandwidth of 6.1%. The axial ratio bandwidth is typical for a microstrip antenna with perturbations, while the VSWR bandwidth is larger than for the circular or rectangular patch with perturbations. A mutual coupling study between two elements shows that the axial ratio is less than 2 dB for interelement spacing greater than 0.55λ_eff, while the VSWR <2 for all spacings considered. A comparison between theory and experiment is provided for a 2×2 element array. The benefits of sequentially rotating the antenna elements in an array environment are presented. The axial ratio and VSWR bandwidths are both increased to 6.1% and 18% for a four-element array. A single-element antenna with two orthogonal feeds to provide both senses of polarization is demonstrated. The ring antenna is small (D/λ₀=0.325), the substrate thickness is thin (H/λ₀~0.035), and the microstrip feed produces a completely planar antenna system, which is compatible with microwave and millimeter integrated circuits (MICs), and monolithic microwave integrated circuits (MMICs)     

The Design of Planar Circulators for Wide-Band Operation

The stripline circulator used in microwave integrated circuits (MIC) is considered one of ferrite planar circuits (two-dimesional circuits). We investigated the optimum shape of a planar circulator for wide-band operation, perceiving the wider freedom of the planar structure in circuit design. The wide-band planar circulator, designed using the powerful contour-integral method is triangular shaped with slightly concave sides. The 20-dB isolation fractional bandwidth of the designed circulator is about 52 percent.     

Adjustable microstrip transformer for use with Josephson devices in mm-wave ICs

A simple remotely adjustable cryogenic impedance transformer employing superconducting inverted microstrip circuits is described. The scheme is particularly suitable for efficiently coupling low impedance (0.1?5 ?) thin-film devices (e.g. Josephson junctions) in planar microwave integrated circuits to waveguide or other superconducting and semiconducting devices at millimetre wavelengths. Preliminary results obtained at 8 mm are presented.     

Millimeter-Wave Integrated Circuits

Monolithic millimeter-wave integrated circuits have been designed and fabricated on semi-insulating GaAs substrates using microstrip transmission lines. Circuits using hybrid techniques have also been constructed on quartz and ceramics. This paper shows that microstrip-line integrated circuits are feasible at millimeter-wave frequencies. Circuit functions have been constructed and tested in the 25- to 100-GHZ range. The loss in microstrip line on semi-insulating GaAs was found to be less than 0.3 dB//lambda/. Couplers from waveguide to microstrip have been made with transmission losses less than 0.5 dB. Monolithic integrated detectors showed 5-dB better sensitivity than a 1N53 diode in a Philips detector mount. Monolithic diodes delivered 1.5 mW at 28 GHz. The results are encouraging and a fully monolithic integrated receiver is under development.     

Approach for heat sinks in monolithic microwave integrated circuits

A planar electrode, placed at the symmetry plane of the odd mode of coupled microstrip, is proposed as a means for heat-sinking active devices in monolithic microwave integrated circuits.     

Millimeter-Wave Integrated Circuits

Monolithic millimeter-wave integrated circuits have been designed and fabricated on semi-insulating GaAs substrates using microstrip transmission lines. Circuits using hybrid techniques have also been constructed on quartz and ceramics. This paper shows that microstrip-line integrated circuits are feasible at millimeter-wave frequencies. Circuit functions have been constructed and tested in the 25- to 100-GHz range. The loss in microstrip line on semi-insulating GaAs was found to be less than 0.3 dB/ /spl lamda/. Couplers from waveguide to microstrip have been made with transmission losses less than 0.5 dB. Monolithic integrated detectors showed 5-dB better sensitivity than a 1N53 diode in a Philips detector mount. Monolithic diodes delivered 1.5 mW at 28 GHz. The results are encouraging and a fully monolithic integrated receiver is under development.     

Millimeter-wave integrated circuits

Monolithic millimeter-wave integrated circuits have been designed and fabricated on semi-insulating GaAs substrates using microstrip transmission lines. Circuits using hybrid techniques have also been constructed on quartz and ceramics. This paper shows that microstrip-line integrated circuits are feasible at millimeter-wave frequencies. Circuit functions have been constructed and tested in the 25- to 100-GHz range. The loss in microstrip line on semi-insulating GaAs was found to be less than 0.3 dB/λ. Couplers from waveguide to microstrip have been made with transmission losses less than 0.5 dB. Monolithic integrated detectors showed 5-dB better sensitivity than a 1N53 diode in a philips detector mount. Monolithic diodes delivered 1.5 mW at 28 GHz. The results are encouraging and a fully monolithic integrated receiver is under development.     

Ferrimagnetic Parts for Microwave Integrated Circuits

Tremendous technological strides have been made in recent years in the development of miniaturized microwave components and modules using microstrip transmission lines in combination with both semiconductor and ferrite technology. This technology growth has been spurred by rapidly increasing microwave systems complexity and diversity and the need for lower cost, more reliable, and smaller microwave assemblies. This paper describes the design and performance of various ferrimagnetic components as functional blocks for use in microwave integrated modules. The design and performance of the following components are described as well as their utilization in various multifunction modules: junction circulators both fixed bias and latching including their use as isolators, duplexers, switches, modulators, and other signal processing circuits; ferrimagnetic planar phase shifters; various combinations of these circuit elements where both all ferrimagnetic and composite ferrimagnetic/dielectric substrates are utilized.     

Ferrite devices and materials

The development and current status of microwave ferrite technology is reviewed in this paper. An introduction to the physics and fundamentals of key ferrite devices is provided, followed by a historical account of the development of ferrimagnetic spinel and garnet (YIG) materials. Key ferrite components, i.e., circulators and isolators, phase shifters, tunable filters, and nonlinear devices are also discussed separately     

Interdigitated Stripline Quadrature Hybrid (Correspondence)

lnterdigitated microstrip couplers consist of three or more parallel striplines with alternate lines tied together. A single ground plane, a single dielectric, and a single layer of metallization are used. Thus the approach is eminently suited for monolithic or hybrid thin-film microwave integrated circuitry. Tight coupling is achieved much more easily than with noninterdigitated edge-coupled lines. Fabrication and tolerance problems make it almost impossible to build noninterdigitated 3-dB edge couplers. Also, current crowding at the edges, which can result in high loss, is much less severe for the interdigitated coupler. Previously, tight coupling in directional couplers for microwave integrated circuits has been achieved by broadside coupling, reentrant sections, tandem sections, or branch-line couplers. Some of the disadvantages of these approaches are narrow bandwidth, large substrate area, and the need for multilayer circuitry. A 3dB directional coupler (quadrature hybrid) for S band has been fabricated in microstrip on 40-mil alumina. A single quarter-wave section was used. The hybrid showed a directivity of over 27 dB, a return loss of over 25 dB, an insertion loss of less than 0.13 dB, and an imbalance of less than 0.25 dB over a 40 percent bandwidth.     

A 12-W GaAs Read-Diode Amplifier at X Band

Multiple-mesa GaAs Read diodes have been incorporated in a single-stage microstrip amplifier module at X band. Stable CW amplification with an output power of 12 W at 4-dB gain and 23.5-percent power-added efficiency has been demonstrated. Design considerations for the amplifier circuits along with the microwave performance results are presented.     

HIgh-Power C-Band Multiple-IMPATT-Diode Amplifiers

The design considerations and performance characteristics of two high-power microwave reflection amplifiers that use multiple silicon IMPATT diodes are presented. The amplifiers employ microstrip hybrid-circuit-type power combiners to combine the individually matched IMPATT diodes. The first unit, a single-stage 4-diode amplifier, produced 8-W output with 6-dB gain while the second 12-diode amplifier gave 15.8-W output at about 9-dB gain. FM and AM noise added by these amplifiers has been measured with each amplifier driven to nearly full output. Use of microstrip hybrid-circuit power combiners appears to offer a simple and economical design approach for the implementation of microwave solid-state power amplifiers using multiple active devices.     

微带电路无源互调干扰问题综述

无源互调（PIM）干扰是微波射频电路面临的主要可靠性问题之一,随着微波射频电路小型集成化发展,微带电路无源互调效应研究开始受到工业界和学术界广泛关注。研究微带电路无源互调机理、评估和抑制方法,对于制备小型化、高可靠性微波射频电路具有重要价值。与腔体部件相比,微带电路的非线性往往是分布的,且与基材选择、制造工艺和器件结构等方面都有重要关系,因此研究难度更大。近年来虽然关注微带电路互调的研究越来越多,但依然难以直接指导微带电路的实际设计。基于此,本文系统论述了近年来微带电路无源互调领域的研究情况,包括非线性机理、仿真建模以及测试诊断等方面,为未来更深入地研究微带电路无源互调效应提供参考。     

A 0.13-μ m CMOS Phase Shifter Using Tunable Positive/Negative Refractive Index Transmission Lines

This letter presents a tunable positive/negative refractive index transmission line (TL) phase shifter utilizing active circuits. It comprises a microstrip TL loaded with series varactors and a shunt monolithic microwave integrated circuit (MMIC) to synthesize a tunable inductor. This implementation increases the phase tuning range and maintains the input and output matching of the phase shifter across the entire phase tuning range, while eliminating the need for bulky passive inductors. The phase shifter is capable of providing both positive and negative phase shifts. The MMIC tunable inductors are fabricated in a 0.13-mum CMOS process and operate from a 1.5-V supply. The phase shifter achieves a phase of -40deg to +34deg at 2.5GHz from a single stage with less than -19dB return loss, and better than 1.1-dB insertion loss at 2.5 GHz. The phase shifter has a 1-GHz bandwidth over which the return loss remains better than 12.1dB